4

cloud physics cloud microphysicscloud dynamics

0◦C warm clouds

cold clouds0◦C

•

•

•

•

•

•

CReSS

2

44 4

4.1

4.1.1

3 1

qv

qc 100 µm

qr

3 kg kg−1 K2.1

∂ρθ

∂t= Adv.θ + Turb.θ − ρw

∂θ

∂z+

ρLv

CpΠ(CNvc − EVcv − EVrv) (4.1)

∂ρqv

∂t= Adv.qv + Turb.qv − ρ (CNvc − EVcv − EVrv) (4.2)

∂ρqc

∂t= Adv.qc + Turb.qc + ρ (CNvc − EVcv − CNcr − CLcr) (4.3)

∂ρqr

∂t= Adv.qr + Turb.qr + ρ (CNcr + CLcr − EVrv) +

∂

∂z(ρUrqr) (4.4)

Adv.φ Turb.φ Lv

J kg−1 Cp J K kg−1 Π (4.4)qr

CNvc condensationEVcv evaporationEVrv evaporationCNcr

autoconversionCLcr collection

1 0.1 0.5mm drizzle

4.1 45

4.1.2

−CNvc + EVcv

Klemp and Wilhelmson (1978) Soong and Ogura (1973)4.2.5

Tetens qvsw

qvsw Tetens

qvsw = ε610.78

pexp

(17.269

Πθ − 273.16Πθ − 35.86

)(4.5)

ε

CNcr, CLcr

CNcr CLcr Kessler (1969)

CNcr = k1 (qc − a) (4.6)

CLcr = k2qcq0.875r (4.7)

k1 = 0.001 s−1 (4.8)

a = 0.001 kg kg−1 (4.9)

k2 = 2.2 s−1 (4.10)

EVrv

Ogura and Takahashi (1971), Klemp and Wilhelmson (1978)

EVrv =1ρ

(1 − qv /qvsw )C (ρqr)0.525

5.4 × 105 + 2.55 × 106 /(pqvsw)(4.11)

C ventilation factor

C = 1.6 + 124.9 (ρqr)0.2046 (4.12)

46 4

Ur

(4.4) Ur Soong and Ogura (1973)

Ur = 36.34 (ρqr)0.1346

(ρ0

ρ

)(4.13)

ρ0 kg m−3 Ur m s−1

z∗ ζ (2.59)

4.2

4.2.1

• 1 2

•

•

•

• → → →

•

•

•

2

•

•

(1999), Murakami et al. (1994), Murakami (1990)

4.2 47

5

θ θ = θ + θ′

qv

qc

qr 100 µm

qi 100 µm

qs 0.1 g cm−3 1 m s−1

qg 0.4 g cm−3 1 4 m s−1

qh 0.9 g cm−3 10 m s−1

CReSS

Ni

Ns

Ng

K kg kg−1 m−3

g kg−1

4.2.2

2.14.1.1

48 4

∂ρθ

∂t= Adv.θ + Turb.θ − ρw

∂θ

∂z+ ρ (Src.θV + Src.θS + Src.θF ) (4.14)

∂ρqv

∂t= Adv.qv + Turb.qv + ρSrc.qv (4.15)

∂ρqc

∂t= Adv.qc + Turb.qc + ρSrc.qc + ρFall.qc (4.16)

∂ρqr

∂t= Adv.qr + Turb.qr + ρSrc.qr + ρFall.qr (4.17)

∂ρqi

∂t= Adv.qi + Turb.qi + ρSrc.qi + ρFall.qi (4.18)

∂ρqs

∂t= Adv.qs + Turb.qs + ρSrc.qs + ρFall.qs (4.19)

∂ρqg

∂t= Adv.qg + Turb.qg + ρSrc.qg + ρFall.qg (4.20)

v, c, r, i, s, g

x y

Adv.φ

Turb.φ

Src.θV

Src.θS

Src.θF

Src.qx

Fall.qx

∂Ni

∂t= Adv.

Ni

ρ+ Turb.

Ni

ρ+ ρSrc.

Ni

ρ+ ρFall.

Ni

ρ(4.21)

∂Ns

∂t= Adv.

Ns

ρ+ Turb.

Ns

ρ+ ρSrc.

Ns

ρ+ ρFall.

Ns

ρ(4.22)

∂Ng

∂t= Adv.

Ng

ρ+ Turb.

Ng

ρ+ ρSrc.

Ng

ρ+ ρFall.

Ng

ρ(4.23)

i, s, g x y

4.2 49

Adv. Nx/ ρ

Turb. Nx/ ρ

Src. Nx/ ρ

Fall. Nx/ ρ

θ 4.14 Src.θV + Src.θS + Src.θF

Src.θV =Lv

CpΠV Dvr (4.24)

Src.θS =Ls

CpΠ(NUAvi + V Dvi + V Dvs + V Dvg) (4.25)

Src.θF =Lf

CpΠ(NUFci + NUCci + NUHci + CLcs + CLcg + CLri + CLrs + CLrg

−MLic − MLsr − MLgr + FRrg − SHsr − SHgr) (4.26)

qv 4.15 Src.qv

Src.qv = −NUAvi − V Dvr − V Dvi − V Dvs − V Dvg (4.27)

qc 4.16 Src.qc

Src.qc = −NUFci − NUCci − NUHci − CLcr − CLcs − CLcg − CNcr + MLic (4.28)

qr 4.17 Src.qr

Src.qr = V Dvr + CLcr − CLri − CLrs − CLrg + CNcr

+MLsr + MLgr − FRrg + SHsr + SHgr (4.29)

qi 4.18 Src.qi

Src.qi = NUAvi + NUFci + NUCci + NUHci

+V Dvi − CLir − CLis − CLig − CNis − MLic + SPsi + SPgi (4.30)

qs 4.19 Src.qs

Src.qs = −SPsi + V Dvs + CLcs + CLrsαrs + CLis − CLsr (1 − αrs) − CLsg

+CNis − CNsg − MLsr − SHsr (4.31)

qg 4.20 Src.qg

Src.qg = −SPgi + V Dvg + PGg + CLri + CLir + (CLrs + CLsr) (1 − αrs)

+CNsg − MLgr + FRrg − SHgr (4.32)

50 4

Ni

ρ4.21 Src.

Ni

ρ

Src.Ni

ρ=

1mi0

NUAvi +Nc

ρqc(NUFci + NUCci + NUHci) + SPN

si + SPNgi

+Ni

ρqi(V Dvi − CLir − CLis − CLig − MLic) − AGN

i − 1ms0

CNis (4.33)

Ns

ρ4.22 Src.

Ns

ρ

Src.Ns

ρ=

Ns

ρqs(V Dvs − MLsr) − CLN

sr (1 − αrs) − CLNsg − AGN

s +1

ms0CNis − CNN

sg (4.34)

Ng

ρ4.23 Src.

Ng

ρ

Src.Ng

ρ=

Ng

ρqg(V Dvg − MLgr) + CLN

ri + CLNrs (1 − αrs) + CNN

sg + FRNrg (4.35)

Lv,Ls,Lf J kg−1 Cp J K kg−1

Π mi0, ms0 kg4.1 4.2.4

NUAvi deposition or sorption nucleationNUFci condensation-freezing nucleationNUCci contact nucleationNUHci homogeneous nucleationSP 2 secondary nucleation of ice crystalsV D vapor deposition, evaporation and sublimationCL collectionPG graupel producitonAG aggregationCN conversionML meltingFR freezingSH shedding of liquid waterSPN 2 secondary nucleation of ice crystalsCLN collectionAGN aggregationCNN conversionFRN freesingαrs 1 − αrs

4.2 51

-VDvr VDvg

NUA vi VD

viVD

vcC

Ncr

CL

cr ML sr,SH sr

CLrs

ML gr,SH gr

CLri,CL Nri,CL rs,CL Nrs,CL rg,FR rg,FR Nrg

NUF ci,NUC ci,NUH ci

ML ic

CLcs

CL is,CN is

SPsi,SP Nsi

CL cg

CL sr,CL sg,CN sg,CN Nsg

SPgi ,SP

Ngi

CL

ir ,CL

ig

AG Ns

AG Ni

Fall. qr

VD

vs

water vapor (qv)

snow (qs,Ns)

cloud water (qc)

rain water (qr)

cloud ice (qi,Ni)

graupel (qg,Ng)

Fall. qg, Fall.( N

g/ )

Fall. qs, Fall. (N

s/ )

4.1.

(4.24),(4.27),(4.28) V Dvc

4.2.5

4.2.3

Marshall and Palmer (1948)λx y nx0

nx (Dx)︸ ︷︷ ︸m−4

= nx0︸︷︷︸m−4

exp( −λx︸︷︷︸m−1

Dx) (4.36)

Marshall-Palmer 2

2 n!(4.36)

Γ (x)

Γ (x) =

∫ ∞

0

exp (−t) tx−1 dt (4.37)

52 4

x 3

fx (Dx)︸ ︷︷ ︸m−1

=1

Γ(νx)

(Dx

Dnx

)νx−1 1Dnx

exp(− Dx

Dnx

)(4.43)

Dx m Γ (νx) 0 ∞ 1νx Dnx

nx (Dx)︸ ︷︷ ︸m−4

= nxt︸︷︷︸m−3

fx (Dx)︸ ︷︷ ︸m−1

(4.44)

nxt x Dx

Dx =∫ ∞

0

Dx fx (Dx) dDx =Γ (νx + 1)

Γ (νx)Dnx = νxDnx (4.45)

(4.38) PP

∫ ∞

0

DPx fx (Dx) dDx =

Γ (νx + P )Γ (νx)

DPnx (4.46)

Γ (x + 1) = xΓ (x) (4.38)

Γ (1) = 1 (4.39)

x n

Γ (n + 1) = n (n − 1) (n − 2) · · · 2 · 1 · Γ (1) = n! (4.40)

Γ

(1

2

)=

√π (4.41)

3∫ ∞

0

D3x exp (−λxDx) dDx =

1

λ4x

Γ (4) =6

λ4x

(4.42)

3 (1999)

4.2 53

(4.36) (4.43) (4.43)

νx = 1 (4.47)

Dnx =1λx

(4.48)

(4.36) (4.46)

∫ ∞

0

DPx λx exp (−λxDx) dDx =

1λP

x

Γ (P + 1) (4.49)

Dx

Dx =1λx

(4.50)

4

Dc =(

6ρqc

πρwNc

) 13

(4.51)

Di =(

6ρqi

πρiNi

) 13

(4.52)

ρw kg m−3 ρi kg m−3

Nc 1 × 108 m−3

nr (Dr) = nr0 exp (−λrDr) (4.53)

ns (Ds) = ns0 exp (−λsDs) (4.54)

ng (Dg) = ng0 exp (−λgDg) (4.55)

nx x y m−4

8 × 106 m−4

4 (1999), Ikawa and Saito (1991), Murakami et al. (1994), Ikawa et al. (1991), Lin et al. (1983)Ferrier (1994)

54 4

mx (Dx) = αuxDβuxx (4.56)

βux = 3

mx = αuxDβuxnx

Γ (νx + βux)Γ(νx)

(4.57)

Ux (Dx) = αuxDβuxx

(ρ0

ρ

)γux

(4.58)

m−4

UxN = αuxDβuxnx

Γ (νx + βux)Γ(νx)

(ρ0

ρ

)γux

(4.59)

Uxq = αuxDβuxnx

Γ (νx + 3 + βux)Γ (νx + 3)

(ρ0

ρ

)γux

(4.60)

(4.47) (4.48) (4.59)(4.60)

UxN = αuxΓ (1 + βux)

λβuxx

(ρ0

ρ

)γux

(4.61)

Uxq = αuxΓ (4 + βux)

6λβuxx

(ρ0

ρ

)γux

(4.62)

ρ0 kg m−3

(4.53) (4.55) 5 x = r, s, g Nx

Nx =∫ ∞

0

nx0 exp (−λxDx) dDx =nx0

λx(4.63)

5Ikawa and Saito (1991)

4.2 55

x

ρqx =∫ ∞

0

π

6ρxD3

xnx0 exp (−λxDx) dDx =πρxnx0

λ4x

(4.64)

2 λx y nx0

λx =(

πρxNx

ρqx

) 13

(4.65)

nx0 = Nx

(πρxNx

ρqx

) 13

(4.66)

x

UxN =1

Nx

∫ ∞

0

Ux (Dx)nx0 exp (−λxDx) dDx

= αuxΓ (1 + βux)

λβuxx

(ρ0

ρ

)γux

(4.67)

(4.61) x

Uxq =1

ρqx

∫ ∞

0

π

6Ux (Dx)D3

xρxnx0 exp (−λxDx) dDx

= αuxΓ (4 + βux)

6λβuxx

(ρ0

ρ

)γux

(4.68)

(4.62) 4.2.6

y m−4 kg m−3

qc ——— αuc = 2.98 × 107, βuc = 2.0, γuc = 1.0 ρw = 1.0 × 103

qr nr0 = 8.0 × 106 αur = 842, βur = 0.8, γur = 0.5 ρw = 1.0 × 103

qi ——— αui = 700, βui = 1.0, γui = 0.33 ρi = 5.0 × 102

qs ns0 = 1.8 × 106 αus = 17, βus = 0.5, γus = 0.5 ρs = 8.4 × 101

qg ng0 = 1.1 × 106 αug = 124, βug = 0.64, γug = 0.5 ρg = 3.0 × 102

56 4

4.2.4

4.2.54.2.7

1 NUAvi, NUFci, NUCci, NUHci

1

→→ NUHci

→ NUAvi

→ NUCci

→ NUFci

NUAvi, NUFci, NUCci, NUHci

1 NUAvi

a 6

Ts w ≤ 0 m s−1

NUAvi =mi0

ρβ2Ni0 exp (β2Ts)

(Si − 1Swi − 1

)B∂Ts

∂zw (4.69)

NUANvi =

NUAvi

mi0(4.70)

(2.59) z∗ ζ

b 7

SSi w ≤ 0 m s−1

NUAvi =mi0

ρ15.25 exp (5.17 + 15.25SSi)

∂SSi

∂zw (4.71)

NUANvi =

NUAvi

mi0(4.72)

(a) z∗ ζ

6Ikawa and Saito (1991), Cotton et al. (1986), Murakami (1990), Ikawa et al. (1991), Murakami et al. (1994), (1999)7Meyers et al. (1992), (1999)

4.2 57

c 8

Ferrier (1994) −5 ◦C Murakami (1990), Cottonet al. (1986) Meyers et al. (1992)

w ≤ 0 m s−1

NUAvi =mi0

ρw

∂Ni

∂z(4.73)

NUANvi =

NUAvi

mi0(4.74)

Ni −5 ◦C

Ni =

⎧⎪⎪⎨⎪⎪⎩

Ni01 exp (β2Ts)(

Si − 1Swi − 1

)B

, T ≥ −5 ◦C

Ni02 exp (a1SSi − b1) , T < −5 ◦C

(4.75)

(a),(b) z∗ ζ

(a) (c)

a1 −5 ◦C Ferrier 12.96b1 −5 ◦C Ferrier 0.639B Huffmann and Vail 4.5mi0 10−12 kgNi0 Fletcher 10−2 m−3

Ni01 −5 ◦C Ferrier 103 m−3

Ni02 −5 ◦C Ferrier 50 m−3

qvsi kg kg−1

qvsw kg kg−1

T KT0 273.16 KTs T0 − T KSi

Swi

SSi Si − 1w z m s−1

β2 Fletcher 0.6 K−1

ρ kg m−3

8Ferrier (1994)

58 4

2 NUFci

Bigg (1953) 9

NUFci = B′ [exp (A′Ts) − 1]ρq2

c

ρwNc(4.76)

NUFNci = B′ [exp (A′Ts) − 1]

qc

ρw(4.77)

A′ Bigg 0.66 K−1

B′ Bigg 100.0 m−3 s−1

Nc 1×108 m−3

T KT0 273.16 KTs T0 − T Kρ kg m−3

ρw 1×103 kg m−3

3 NUCci

10 3

• Brownian diffusion

• diffusiophoresis

• thermophoresis

[dNc

dt

]b

= F1Dar (4.78)

[dNc

dt

]v

= F1F2RvT

Lv(4.79)

[dNc

dt

]t

= F1F2ft (4.80)

9 (1999), Ikawa and Saito (1991)10 (1999), Cotton et al. (1986), Young (1974)

4.2 59

F1 = 2πDcNcNar (4.81)

F2 =κa

p(T − Tcl) (4.82)

ft =0.4 [1 + 1.45Kn + 0.4 exp (−1 /Kn )] (κ + 2.5Knκa)

(1 + 3Kn) (2κ + 5κaKn + κa)(4.83)

Kn Knudsen

Kn = λa0p00

T00Ra

T

p(4.84)

Dar

Dar =kTcl

6πRaµ(1 + Kn) (4.85)

Tcl Nar11

Nar = Na0 (270.16 − Tcl)1.3 (4.86)

NUCNci =

1ρ

([dNc

dt

]b

+[dNc

dt

]v

+[dNc

dt

]t

)(4.87)

NUCci =ρqc

NcNUCN

ci (4.88)

3

Dc mk 1.380658×10−23 J K−1

Lv J kg−1

Na0 2×105 m−3

Nc 1×108 m−3

11Cotton et al. (1986)

60 4

p Pap00 101325 PaRa 3×10−7 mRv 461.0 J K−1 kg−1

T KT00 293.15 KTcl Kκ 2.4 × 10−2 J m−1 s−1 K−1

κa J m−1 s−1 K−1

λa0 p00, T00 6.6×10−8 mµ kg m−1 s−1

ρ kg m−3

4 NUHci

−40 ◦C 12

NUHNci =

1ρ

Nc

2∆t(4.89)

NUHci =qc

2∆t(4.90)

2∆t

Ferrier,1994

2 SP

2

• Hallett and Mossop, 1974

• Vardiman, 1978

• Hobbs and Rangno, 1985

1 Hallett-Mossop rime splintering mechanism13 2

SPNsi =

1ρ× 3.5 × 108f (Ts) CLcs (4.91)

SPsi = mi0SPNsi (4.92)

12Ikawa and Saito (1991), Ferrier (1994)13 (1999), Ikawa and Saito (1991), Cotton et al. (1986)

4.2 61

SPNgi =

1ρ× 3.5 × 108f (Tg)CLcg (4.93)

SPgi = mi0SPNgi (4.94)

2f (Tx) Tx Ts Tg

f (Tx) =

⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩

0, Tx > 270.16 K

Tx − 268.162

, 268.16 ≤ Tx ≤ 270.16 K

268.16 − Tx

3, 265.16 ≤ Tx ≤ 268.16 K

0, Tx < 265.16 K

(4.95)

Cotton et al. (1986) (72) f (Tx) (4.95)(4.95) Tx = 268.16 K f (Tx) = 0 Ikawa et al. (1991), Ikawa

and Saito (1991)

f (Tx) =

⎧⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎨⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪⎩

0, Tx ≥ 270.16 K

270.16 − Tx

2, 268.16 < Tx < 270.16 K

1, Tx = 268.16 K

Tx − 265.163

, 265.16 ≤ Tx < 268.16 K

0, Tx < 265.16 K

(4.96)

Tx = 268.16 K f (Tx) = 1 −5 ◦C

CLcg s−1

CLcs s−1

mi0 10−12 kgTs KTg KTx Kρ kg m−3

62 4

V D

→→

→→ V Dvr < 0

→ V Dvi > 0→ V Dvs > 0→ V Dvg > 0→ V Dvh > 0

→ V Dvi < 0→ V Dvs < 0→ V Dvg < 0→ V Dvh < 0

1 V Drv

V Dvr = −V Drv =

⎧⎪⎪⎨⎪⎪⎩

2π

ρ(Sw − 1)Gw (T, p)V ENTr, Sw − 1 < 0

0, Sw − 1 ≥ 0

(4.97)

14

Gw (T, p) =( L2

v

κRvT 2+

1ρqvswDv

)−1

(4.98)

V ENTr = nr0

[0.78λ−2

r + 0.31S13c ν− 1

2 α12urΓ

(5 + βur

2

)λ− (5+βur)

2r

(ρ0

ρ

) 14]

(4.99)

14 (1999)

4.2 63

Dv m2 s−1

Lv J kg−1

nr0 y 8.0 × 106 m−4

qvsw kg kg−1

Rv 461.0 J K−1 kg−1

Sc 0.6Sw − 1T Kαur 842 m1−βur s−1

βur 0.8λr m−1

κ 2.4×10−2 J m−1 s−1 K−1

ν m2 s−1

ρ kg m−3

ρ0 kg m−3

2 V Dvs, V Dvg15

x = s, g

T < T0

V Dvx =2π

ρ(Si − 1)Gi (T, p) V ENTx − LsLf

κRvT 2Gi (T, p)CLcx (4.100)

T > T0 MLxr < 0 MLxr ≥ 0

V Dvx =

⎧⎪⎪⎨⎪⎪⎩

2π

ρ(Sw − 1) Gw (T, p)V ENTx, MLxr ≥ 0

2πDv (qv − qvs (T0))V ENTx, MLxr < 0

(4.101)

Gi (T, p) =( L2

s

κRvT 2+

1ρqvsiDv

)−1

(4.102)

15 (1999), Ikawa and Saito (1991), Lin et al (1983)

64 4

Gw (T, p) (4.98) x = s, g

V ENTx = nx0

[0.78λ−2

x + 0.31S13c ν− 1

2 α12uxΓ

(5 + βux

2

)λ− (5+βux)

2x

(ρ0

ρ

) 14]

(4.103)

CLcg s−1

CLcs s−1

Dv m2 s−1

Lf J kg−1

Ls J kg−1

ng0 y m−4

ns0 y m−4

MLgr s−1

MLsr s−1

qvs (T0) kg kg−1

qvsi kg kg−1

Rv 461.0 J K−1 kg−1

Sc 0.6Si − 1Sw − 1T KT0 273.16 Kαug 124 m1−βug s−1

αus 17 m1−βus s−1

βug 0.64βus 0.5λg m−1

λs m−1

κ 2.4×10−2 J m−1 s−1 K−1

ν m2 s−1

ρ kg m−3

ρ0 kg m−3

3 V Dvi16

V Dvi =qv − qvsi

qvsw − qvsia1 (mi)

a2 Ni

ρ(4.104)

16Ikawa and Saito (1991), Ikawa et al. (1991)

4.2 65

mi

mi =qiρ

Ni(4.105)

a1, a2 Koenig (1971) 1◦C

a1

Tc◦C 0 -10 -20 -30

0.0 0.000 7.434 ×10−10 9.115 ×10−10 5.333 ×10−10

< -1.0 7.939 ×10−11 1.812 ×10−09 4.876 ×10−10 4.834 ×10−10

< -2.0 7.841 ×10−10 4.394 ×10−09 3.473 ×10−10

< -3.0 3.369 ×10−09 9.145 ×10−09 4.758 ×10−10

< -4.0 4.336 ×10−09 1.725 ×10−10 6.306 ×10−10

< -5.0 5.285 ×10−09 3.348 ×10−08 8.573 ×10−10

< -6.0 3.728 ×10−09 1.725 ×10−08 7.868 ×10−10

< -7.0 1.852 ×10−09 9.175 ×10−09 7.192 ×10−10

< -8.0 2.991 ×10−10 4.412 ×10−09 6.153 ×10−10

< -9.0 4.248 ×10−10 2.252 ×10−09 5.956 ×10−10

a2

Tc◦C 0 -10 -20 -30

0.0 0.000 4.318 ×10−01 4.447 ×10−01 4.382 ×10−01

< -1.0 4.006 ×10−01 4.771 ×10−01 4.126 ×10−01 4.361 ×10−01

< -2.0 4.831 ×10−01 5.183 ×10−01 3.960 ×10−01

< -3.0 5.320 ×10−01 5.463 ×10−01 4.149 ×10−01

< -4.0 5.307 ×10−01 5.651 ×10−01 4.320 ×10−01

< -5.0 5.319 ×10−01 5.813 ×10−01 4.506 ×10−01

< -6.0 5.249 ×10−01 5.655 ×10−01 4.483 ×10−01

< -7.0 4.888 ×10−01 5.478 ×10−01 4.460 ×10−01

< -8.0 3.894 ×10−01 5.203 ×10−01 4.433 ×10−01

< -9.0 4.047 ×10−01 4.906 ×10−01 4.413 ×10−01

qvsi kg kg−1

qvsw kg kg−1

Tc◦C

ρ kg m−3

66 4

CL

qc qi CLci

qc qs CLcs

qc qg CLcg

qc qr CLcr

qr qi CLri

qr qs CLrs

qr qg CLrg

qi qr CLir

qi qs CLis

qi qg CLig

qs qr CLsr

qs qg CLsg

17

1 CLxy x, y = r, s, g; x �= y

CLxy = π2 ρx

ρExy

√(Ux − Uy

)2 + αUxUynx0ny0

(5

λ6xλy

+2

λ5xλ2

y

+0.5

λ4xλ3

y

)(4.106)

CLNxy =

π

2ρExy

√(Ux − Uy

)2 + αUxUynx0ny0

(1

λ3xλy

+1

λ2xλ2

y

+1

λxλ3y

)(4.107)

x, y = r, s, g; x �= y

Exy

nx0 x y m−4

Ux x m s−1

α 0.04λx x m−1

ρ kg m−3

ρx x kg m−3

17 (1999), Lin et al. (1983), Murakami (1990), Ikawa and Saito (1991)

4.2 67

2 CLcy, CLiy y = r, s, g

CLxy =π

4Exy ny0 qx αuy Γ (3 + βuy) λ−(3+βuy)

y

(ρ0

ρ

) 12

(4.108)

Eiy

Ecy

Ecy =Stk2

(Stk + 0.5)2(4.109)

Stk Ikawaand Saito (1991)

Stk = D2cρw

Uy

9µDy(4.110)

Dc mDy y mny0 y y m−4

Uy y m s−1

αuy y m1−βuy s−1

βuy y

λy y m−1

µ kg m−1 s−1

ρ kg m−3

ρ0 kg m−3

ρw 1×103 kg m−3

3 CLri

18

CLri =π2

24Eir Ni nr0 αur Γ (6 + βur) λ−(6+βur)

r

(ρ0

ρ

) 12

(4.111)

18 (1999)

68 4

CLNri =

π

4ρEir Ni nr0 αur Γ (3 + βur) λ−(3+βur)

r

(ρ0

ρ

) 12

(4.112)

Eir 1.0nr0 y 8.0 × 106 m−4

αur 842 m1−βur s−1

βur 0.8λr m−1

ρ kg m−3

ρ0 kg m−3

4 Exy19

(1) (3) Exy

Ecr Stk2/

(Stk + 0.5)2

Ecs Stk2/

(Stk + 0.5)2

Ecg Stk2/

(Stk + 0.5)2

Ers 1.0Erg 1.0Eir 1.0Eis 1.0Eig 0.1Esr 1.0Esg 0.001

5 αrs

0 ◦C(4.31) (4.32) αrs mr ms

αrs =m2

s

m2s + m2

r

(4.113)

mr ms

mr = ρr

(4λr

)3

(4.114)

19Ikawa and Saito (1991), Ikawa et al. (1991)

4.2 69

ms = ρs

(4λs

)3

(4.115)

(1 − αrs)(4.113)

PG

PGdry = CLcg + CLrg + CLig + CLsg (4.116)

20

PGwet =2π [κTs + LvDvρ (qvs (T0) − qv)]

ρ (Lf − CwTs)V ENTg +

(CL′

ig + CL′sg

) (1 +

CiTs

Lf − CwTs

)(4.117)

V ENTg (4.103)PGdry PGwet

PGg = PGdry, PGdry ≤ PGwet (4.118)

PGg = PGwet, PGdry > PGwet (4.119)

CLcg s−1

CLig s−1

CL′ig s−1

CLrg s−1

CLsg s−1

20 (1999)

70 4

CL′sg s−1

Ci 2.0×103 J K−1kg−1

Cw 4.17×103 J K−1kg−1

Dv m2 s−1

Lf J kg−1

Lv J kg−1

qvs (T0) kg kg−1

T KT0 273.16 KTs T0 − T Kκ 2.4×10−2 J m−1 s−1 K−1

ρ kg m−3

AG

2

1 AGNi

21

AGNi =

[d

dt

(Ni

ρ

)]aggr

= − c1

2ρNi (4.120)

c1

c1 =ρqiαuiEiiX

ρi

(ρ0

ρ

) 13

(4.121)

Eii 0.1X 0.25αui 700 m1−βui s−1

βui 1.0ρ kg m−3

ρ0 kg m−3

ρi 5.0×102 kg m−3

21 (1999), Ikawa and Saito (1991)

4.2 71

2 AGNs

22

qs

Ns

AGNs =

[d

dt

(Ns

ρ

)]aggr

= −1ρ

αusEssI (βus)4 × 720

π1−βus

3 ρ2+βus

3 ρ−2−βus

3s q

2+βus3

s N4−βus

3s (4.122)

I (βus) =∫ ∞

0

∫ ∞

0

x3y3 (x + y)2∣∣xβ

us − yβus

∣∣ exp [− (x + y)] dxdy (4.123)

Gauss 23

I (βus) = Γ (βus) 21−d3∑

i=1

Ci

[F (1, d; 8 − i; 0.5)

7 − i− F (1, d; 4 + βus; 0.5)

3 + βus + i

](4.128)

d = 10 + βus

C1 = 1

C2 = 3

C3 = 1

I (βus) Ikawa and Saito, 1991; Mizuno, 1990

22 (1999), Ikawa and Saito (1991)23 hypergeometric function 2 x = 0, 1,∞1

F (x, a; b; c) = 1 +a · b

c

x

1!+

a (a + 1) b (b + 1)

c (c + 1)

x2

2!+ · · · (4.124)

c �= 0,−1,−2, · · ·

(a)n = a (a + 1) (a + 2) · · · (a + n − 1) =(a + n − 1)!

(a − 1)!(4.125)

(a)0 = 1 (4.126)

F (x, a; b; c) =

∞∑n=0

(a)n (b)n

(c)n

xn

n!(4.127)

72 4

βus 0.4 0.5 0.6

I (βus) 1108 1610 2566

Ess 0.1αus 17 m1−βus s−1

βus 0.5ρ kg m−3

ρs 8.4×101 kg m−3

CN

CNxy Kessler (1969)

qc qr CNcr

qi qs CNis

qs qg CNsg

qs qh CNsh

qg qh CNgh

qs qg CNsg

qs qh CNsh

qg qh CNgh

CNcr, CNis, CNsg

1 CNcr24

Kessler (1969) Berry (1968), Berry and Reinhardt (1974)

a Berry 1968 , Berry and Reinhardt 1974 25

Berry (1968), Berry and Reinhardt (1974)

CNcr =

⎧⎪⎪⎪⎨⎪⎪⎪⎩

0.104gEcc

µ (Ncρw)13

(ρ4q7

c

) 13 , qc ≥ qcm

0, qc < qcm

(4.129)

24 (1999), Lin et al. (1983), Ferrier (1994), Ikawa and Saito (1991)25 (1991)

4.2 73

Ecc = 0.55qcm

qcm =ρw

6ρπD3

cmNc (4.130)

Dcm Dcm = 20 µm Nc

Nc = 108 m−3

b Kessler 1969 26

CNcr = a (qc − qcm)H (qc − qcm) (4.131)

H a = 10−3 s−1 , qcm = 10−3 kg kg−1 Cottonand Anthes (1989) a qcm qc

a = πEccUdcNcD2c = 1.3 × q

43c N

− 13

c

(ρ0

ρ

)(4.132)

qcm =4πρwNcD

3cm

3ρ= 4 × 10−12Nc, Dcm = 10−5 m (4.133)

c Lin et al. 1983

Berry (1968) Lin et al. (1983)

CNcr = ρ (qc − qcm)2[1.2 × 10−4 + 1.569 × 10−12 Nc

σ2(qc−qcm)

](4.134)

σ2 = 0.15 qcm = 2 × 10−3 kg kg−1

(a) (c)

g 9.8 m s−2

Nc 1×108 m−3

µ kg m−1 s−1

ρ kg m−3

ρ0 kg m−3

ρw 1×103 kg m−3

26Ikawa and Saito (1991)

74 4

2 CNis

227

Ri Rs0 ∆tis1

∆tis1 =R2

s0 − R2i

2a1ρi (4.135)

a1 (4.100) (4.97)

a1 = (Si − 1)( L2

s

κRvT 2+

1ρqvsiDv

)−1

(4.136)

CNdepis

CNdepis =

qi

∆tis1(4.137)

Ri Rs0 ∆tis2

ρi = const. Ni Ni (Ri /Rs0 )3

∆tis2 =2c1

log(

Rs0

Ri

)3

(4.138)

c1 (4.121)

CNaggis =

qi

∆tis2(4.139)

CNis

CNis = CNdepis + CNagg

is (4.140)

27 (1999), Murakami (1990), Ikawa and Saito (1991)

4.2 75

Dv m2 s−1

Ls J kg−1

qvsi kg kg−1

Rv 461.0 J K−1 kg−1

Si − 1T Kκ 2.4×10−2 J m−1 s−1 K−1

ρ kg m−3

ρi 5.0×102 kg m−3

3 CNsg

riming embryo 28 riming

CN rimsg =

3πρ0 (ρqc)2 E2

csα2usΓ (2βus + 2)

8ρ (ρg − ρs)λ2βus+1s

Ns (4.141)

embryo

CNembsg =

ρs

ρg − ρs

3πρ0 (ρqc)2 E2

csα2usΓ (2βus + 2)

8ρ (ρg − ρs)λ2βus+1s

Ns (4.142)

CNsg

CNsg = CN rimsg + CNemb

sg

=ρg

ρg − ρs

3πρ0 (ρqc)2E2

csα2usΓ (2βus + 2)

8ρ (ρg − ρs)λ2βus+1s

Ns (4.143)

CNNsg =

ρ0

ρ

[3παusEcsρqc

2 (ρg − ρs)

]Ns (4.144)

28Murakami (1990)

76 4

Ecs Stk2/

(Stk + 0.5)2

αus 17 m1−βus s−1

βus 0.5λs m−1

ρ kg m−3

ρ0 kg m−3

ρg 3.0×102 kg m−3

ρs 8.4×101 kg m−3

ML

1 MLic

T > T0

Tc > T0

MLic =qi

2∆t(4.145)

2∆t

2 MLsr, MLgr

MLxr x = s, g 29

MLxr =

⎧⎪⎪⎪⎨⎪⎪⎪⎩

2π

ρLf[κTc + LvDvρ (qv − qvs (T0))]V ENTx +

CwTc

Lf(CLcx + CLrx) , T > T0

0, T ≤ T0

(4.146)

T > T0 MLxr < 0 MLxr = 0V ENTx (4.103)

(1),(2)

CLcx x s−1

CLrx x s−1

Cw 4.17×103 J K−1 kg−1

29Ikawa and Saito (1991)

4.2 77

Dv m2 s−1

Lf J kg−1

Lv J kg−1

qvs (T0) kg kg−1

T KT0 273.16 KTc

◦Cκ 2.4×10−2 J m−1 s−1 K−1

ρ kg m−3

FR

FRrg Bigg (1953) 30

FRrg = 20π2B′nr0ρw

ρ[exp (A′Ts) − 1]λ−7

r (4.147)

FRNrg =

π

6ρB′nr0 [exp (A′Ts) − 1]λ−4

r (4.148)

A′ Bigg 0.66 K−1

B′ Bigg 100.0 m−3 s−1

nr0 y 8.0 × 106 m−4

T KT0 273.16 KTs T0 − T Kλr m−1

ρ kg m−3

ρw 1×103 kg m−3

30Lin et al. (1983), (1999)

78 4

SH

T > T0

SHsr = CLcs + CLrs (4.149)

SHgr = CLcg + CLrg (4.150)

T ≤ T0

SHgr = CLcg + CLrg + CL′ig + CL′

sg − PGwet (4.151)

Ferrier (1994)

CLcg s−1

CLcs s−1

CLrg s−1

CLrs s−1

CL′ig s−1

CL′sg s−1

PGwet s−1

T KT0 273.16 K

8mm

λr

4.2 79

4.2.5

31

∗

∆qc = q∗v − q∗vsw (4.152)

∆qc > 0 q∗c > 0

θt+∆t = θ∗ + γ (q∗v − q∗vsw)/(

1 + γ∂q∗vsw

∂θ∗

)(4.153)

qt+∆tv = q∗v +

(θ∗ − θt+∆t

)/γ (4.154)

qt+∆tc = q∗v + q∗c − qt+∆t

v (4.155)

θ, qv, qc qt+∆tc > 0 ∗

(4.153) (4.155)γ ≡ Lv/ (CpΠ)

qt+∆tc ≤ 0

θt+∆t = θ∗ − γq∗c (4.156)

qt+∆tv = q∗v + q∗c (4.157)

qt+∆tc = 0 (4.158)

Cp 1004 J K kg−1

Lv J kg−1

qvsw kg kg−1

Π

31Soong and Ogura (1973)

80 4

4.2.6

Fall.qx =1ρ

∂ρUxqqx

∂z(4.159)

x Uxq (4.68)

Fall.Nx

ρ=

1ρ

∂NxUxN

∂z(4.160)

x UxN (4.67)

CFL∆tlim

∆tlim =∆z

Uxq(4.161)

2∆t

∆tfall =2∆t

int (2∆t/∆tlim) + 1, int (4.162)

CFL 1

z∗ ζ

4.2.7

qvsw, qvsi32

qvsw = ε610.78

pexp

(17.269

T − T0

T − 35.86

)kg kg−1 (4.163)

qvsi = ε610.78

pexp

(21.875

T − T0

T − 7.86

)kg kg−1 (4.164)

32Orville and Kopp (1977), Murray (1966)

4.2 81

Lv,Ls,Lf

Lv = 2.50078 × 106

(T0

T

)(0.167+3.67×10−4T)J kg−1 (4.165)

Ls = 2.834 × 106 + 100 (T − T0) J kg−1 (4.166)

Lf = 3.34 × 105 + 2500 (T − T0) J kg−1 (4.167)

ν, µ

ν = 1.328 × 10−5 p0

p

(T

T0

)1.754

m2 s−1 (4.168)

µ = ρν kg m−1 s−1 (4.169)

Dv

Dv = 2.23 × 10−5 p0

p

(T

T0

)1.81

m2 s−1 (4.170)

p Pap0 101325 PaT KT0 273.16 Kε 0.622ρ kg m−3